Recent developments in the art of polymerization have enabled the production of solid, amorphous polypropylene and co-polymers of ethylene and propylene that have many of the physical characteristics of rubber and, in fact, can be used as an improved replacement for rubber in many applications. These amorphous polymers and co-polymers are thermoplastic and soluble in many organic solvents. Like rubber, these polymers and co-polymers must be cross-linked, i.e. vulcanized, in order to render the polymers and co-polymers useful for many of the intended uses.
Almost all of the plastic resin sold in the market today is in the form of pellets. Plastic resins are sold in the form of pellets to improve transportation, handling, safety and end-user material processability characteristics. Reactor granular resin is thus melted and extruded and made to flow through dies before being cut into pellets. The extrusion process serves as a step for the addition of performance additives for the required stability and material properties. The size, shape, and uniformity of the pellets are important and measures of these pellet characteristics are standard quality assurance/quality control (QA/QC) tests to be met during production. The pelletizing step is important from an operational standpoint. Any upset or malfunction of the pelletizer can result in process shutdown and halt manufacturing with serious financial consequences, especially for large extrusion lines. The pelletizing step becomes an important component of the production line of any polyolefin production facility. The pelletizing step is not to be taken lightly in cases where the polymer renders difficult cut.
A need exists for a polymer that possesses many of the characteristics of rubber, but is reversibly cross-linked, and therefore recyclable.
A need exists for a polymer capable of providing improved strength, comparable to that of conventional elastomers, while having high ductility and large insulating R-values.
A need exists for a reversibly cross-linked polymer possessing enhanced reversibility through blending with a nano-clay.
The present embodiments meet these needs.